The invention relates to a colour display tube comprising an envelope having a substantially rectangular display window which is provided with an upright edge, and a substantially rectangular colour selection electrode having a great number of apertures, which electrode is suspended from pins secured in the upright edge of the display window by means suspension means, each of which means comprises a resilient element which is fixedly connected to the colour selection electrode, and a slide plate having an aperture which is rigidly secured to the resilient element, each pin having a free end portion which partly projects from the aperture in the slide plate.
The invention also relates to a method of manufacturing such a colour display tube.
Such a colour display tube is known from British Patent Specification 2,097,996. Therein, each suspension means comprises a wire spring which is connected at one end to the colour selection electrode and at the other end urges the flat resilient element onto the free end portion of the pin. During the suspension of the colour selection electrode, the slide plate is slidably secured relative to the flat resilient element, the wire spring being necessary to retain the slide plate before it is rigidly secured to the flat resilient element.
In order to obtain a proper suspension of the colour selection electrode, the wire spring must firmly urge the flat resilient element onto the free end portion. This pressure should be sufficiently large that in the case of vibrations or shocks the colour selection electrode is not subject to an unfavourable change in position. Since the wire spring is secured to the colour selection electrode at one end, the colour selection electrode may be subject to deformation when the pressure exerted by the wire spring is too large. For this reason, a wire spring having a limited pressure is used in practice, the disadvantage thereof being, however, that in the case of vibrations and shocks the colour selection electrode may assume a position which differs from that when the colour selection electrode is properly suspended.